U.S. patent application number 09/796005 was filed with the patent office on 2002-08-29 for method and apparatus for monitoring granule coloration on an asphalt-coated sheet.
Invention is credited to Phillips, John D., Rodenbaugh, David R..
Application Number | 20020119244 09/796005 |
Document ID | / |
Family ID | 25167005 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020119244 |
Kind Code |
A1 |
Rodenbaugh, David R. ; et
al. |
August 29, 2002 |
Method and apparatus for monitoring granule coloration on an
asphalt-coated sheet
Abstract
A method of producing asphalt strip shingles includes
continuously coating a substrate with asphalt to form an asphalt
coated sheet, moving the asphalt coated sheet in a machine
direction, depositing blend drops of blend drop granules onto the
asphalt coated sheet from a blender, providing a signal indicative
of the presence of the blend drops at a location downstream from
the blender, sensing the color of the blend drops at the downstream
location with a sensor, comparing the sensed color of the blend
drops with a reference color, and providing a signal indicative of
the comparison.
Inventors: |
Rodenbaugh, David R.;
(Baltimore, OH) ; Phillips, John D.; (Pataskala,
OH) |
Correspondence
Address: |
OWENS CORNING
2790 COLUMBUS ROAD
GRANVILLE
OH
43023
US
|
Family ID: |
25167005 |
Appl. No.: |
09/796005 |
Filed: |
February 28, 2001 |
Current U.S.
Class: |
427/8 ; 427/186;
427/188 |
Current CPC
Class: |
B05D 1/30 20130101; B05D
5/06 20130101; B05D 2451/00 20130101; E04D 2001/005 20130101; E04D
1/26 20130101; B05D 2451/00 20130101; B05D 2401/32 20130101 |
Class at
Publication: |
427/8 ; 427/186;
427/188 |
International
Class: |
B05D 005/02; B05D
007/00 |
Claims
What is claimed is:
1. A method of producing asphalt strip shingles comprising:
depositing blend drops of blend drop granules onto an asphalt
coated sheet; sensing the color of the blend drops; comparing the
sensed color of the blend drops with a reference color; and
providing a signal indicative of the comparison.
2. The method of claim l in which the depositing step includes
depositing blend drops from a plurality of hoppers, the blend drops
from each hopper being of a different color from the blend drops
from the other hoppers, and further including applying background
granules to the asphalt coated sheet after applying the blend drops
to form a granule coated sheet.
3. The method of claim 2 including moving the granule coated sheet
in a machine direction and moving the sensor across the granule
coated sheet in a cross-machine direction to sense the color of the
blend drops.
4. The method of claim 2 including sensing the color of the blend
drops from one of the hoppers for a period of time, and then
switching to sensing the color of blend drops from another of the
hoppers.
5. The method of claim 1 including adjusting the color of the
granules from the hopper in response to the sensed color of the
blend drop.
6. The method of claim 1 including adjusting the speed of the
asphalt coated sheet in response to the sensed color of the blend
drop.
7. The method of claim 1 in which the sensing involves viewing an
area of the blend drop that is less than the total area of the
blend drop.
8. The method of claim 1 in which the depositing step includes
depositing blend drops from a plurality of hoppers, the blend drops
from each hopper being of a different color from the blend drops
from the other hoppers, and further including applying background
granules to the asphalt coated sheet after applying the blend drops
to form a granule coated sheet, and further including moving the
granule coated sheet in a machine direction and moving the sensor
across the granule coated sheet in a cross-machine direction to
sense the color of the blend drops, and further including sensing
the color of the blend drops from one of the hoppers for a period
of time, and then switching to sensing the color of blend drops
from another of the hoppers.
9. A method of producing asphalt strip shingles comprising:
continuously coating a substrate with asphalt to form an asphalt
coated sheet; moving the asphalt coated sheet in a machine
direction; depositing blend drops of blend drop granules onto the
asphalt coated sheet from a blender; providing a signal indicative
of the presence of the blend drops at a location downstream from
the blender; sensing the color of the blend drops at the downstream
location with a sensor; comparing the sensed color of the blend
drops with a reference color; and providing a signal indicative of
the comparison.
10. The method of claim 9 including using a timing device to
provide the signal indicative of the presence of the blend drops at
the downstream location.
11. The method of claim 9 including using a light source as part of
the step of sensing the color of the blend drops.
12. The method of claim 9 in which the sensor is an optical
sensor.
13. The method of claim 9 in which the depositing step includes
depositing blend drops from a plurality of hoppers, the blend drops
from each hopper being of a different color from the blend drops
from the other hoppers, and further including applying background
granules to the asphalt coated sheet after applying the blend drops
to form a granule coated sheet.
14. The method of claim 13 including moving the granule coated
sheet in a machine direction and moving the sensor across the
granule coated sheet in a cross-machine direction to sense the
color of the blend drops.
15. The method of claim 13 including sensing the color of the blend
drops from one of the hoppers for a period of time, and then
switching to sensing the color of blend drops from another of the
hoppers.
16. The method of claim 9 including using a timing device to
provide the signal indicative of the presence of the blend drops at
the downstream location, using a light source as part of the step
of sensing the color of the blend drops, and wherein the depositing
step includes depositing blend drops from a plurality of hoppers,
the blend drops from each hopper being of a different color from
the blend drops from the other hoppers, and further including
applying background granules to the asphalt coated sheet after
applying the blend drops to form a granule coated sheet.
17. The method of claim 16 including moving the granule coated
sheet in a machine direction and moving the sensor across the
granule coated sheet in a cross-machine direction to sense the
color of the blend drops.
18. The method of claim 16 including sensing the color of the blend
drops from one of the hoppers for a period of time, and then
switching to sensing the color of blend drops from another of the
hoppers.
19. A method of producing asphalt strip shingles comprising: making
shingles of a first color on a shingle machine including
programming a controller with a reference color, depositing blend
drops of blend drop granules onto an asphalt coated sheet, sensing
the color of the blend drops, comparing the sensed color of the
blend drops with the reference color, and providing a signal
indicative of the comparison; switching the shingle machine to make
shingles of another color; and switching back the shingle machine
to again make shingles of the first color, using the programmed
reference color for comparing the color of the blend drops.
Description
TECHNICAL FIELD
[0001] This invention relates to the manufacture of shingles, such
as roofing shingles, and in particular, to shingles having granules
of a background color and blend drops of granules of various shades
of colors that are different from the background color. More
particularly, this invention pertains to a method of monitoring the
color of various portions of the shingle.
BACKGROUND OF THE INVENTION
[0002] Asphalt-based roofing materials, such as roofing shingles,
roll roofing and commercial roofing, are installed on the roofs of
buildings to provide protection from the elements, and to give the
roof an aesthetically pleasing look. Typically, the roofing
material is constructed of a substrate such as a glass fiber mat or
an organic felt, an asphalt coating on the substrate, and a surface
layer of granules embedded in the asphalt coating.
[0003] A common method for the manufacture of asphalt shingles is
the production of a continuous sheet of asphalt material followed
by a shingle cutting operation which cuts the material into
individual shingles. In the production of asphalt sheet material,
either a glass fiber mat or an organic felt mat is passed through a
coater containing hot liquid asphalt to form a tacky, asphalt
coated sheet. Subsequently, the hot asphalt coated sheet is passed
beneath one or more granule applicators which discharge protective
and decorative surface granules onto portions of the asphalt sheet
material.
[0004] In the manufacture of colored shingles, two types of
granules are typically employed. Headlap granules are granules of
relatively low cost used for the portion of the shingle that will
be covered up on the roof. Colored granules or prime granules are
of relatively higher cost and are applied to the portion of the
shingle that will be exposed on the roof.
[0005] To provide a color pattern of pleasing appearance, the
colored portion of the shingles may be provided with areas of
different colors. Usually the shingles have a background color and
a series of granule deposits of different colors or different
shades of the background color. A common method for manufacturing
the shingles is to discharge blend drops onto spaced areas of the
tacky, asphalt coated sheet. Background granules are then
discharged onto the sheet and they adhere to the tacky, asphalt
coated areas of the sheet between the granule deposits formed by
the blend drops. The term "blend drop", as used herein, refers to
the flow of granules of different colors or different shades of
color (with respect to the background color) that is discharged
from a granule blend drop applicator onto the asphalt coated sheet.
The patch or assemblage of the blend drop granules on the asphalt
coated sheet is also referred to as the "blend drop".
[0006] The apparatus for depositing granules onto the asphalt
coated sheet is referred to as a blender, which can be comprised of
a series of hoppers positioned to drop granules onto the sheet. In
a typical blend drop shingle operation, the blender includes four
hoppers that periodically deposit blend drops of granules of four
different shades. The blender also includes a fifth hopper that
drops background granules on the areas of the asphalt coated sheet
that have not been covered by granules from the first four
hoppers.
[0007] Various types of granule dispensing hoppers are known for
use in granule blenders. One type of dispensing hopper is a fluted
roll. Another type is a pneumatically assisted and controlled
hopper as disclosed in U.S. Pat. No. 5,520,889 to Burton et al.
Since the manufacture of shingles is carried out at high continuous
line speeds of hundreds of feet per minute, coordination and timing
for the granule deposits from the various hoppers is imperative.
The blender is usually operated by an electronic blender controller
that provides signals to the various granule hoppers to impart the
proper sequencing and duration of the blend drops of each blend
drop color, and of the background color.
[0008] The various shades or colors in each of the hoppers are
typically created by mixing colored granules of different colors
from several different supplies of granules, each of which is a
pure or single color. For example, the first blend drop may be made
by mixing three parts pure brown granules and one part pure black
granules. The second blend drop may be made by mixing four parts
pure brown granules and two parts pure white granules. Other
combinations may be used for the third and fourth blend colors. The
fifth hopper may contain background granules that are a color
reflecting a combination of the granules from the first four
hoppers.
[0009] One of the problems associated with the manufacture of
shingles with blend drops is that the shade or color can deviate
from the designed shade or color, and therefore be out of
specification. This can occur because of incomplete mixing of the
granules, or from a malfunction of the blender or the hopper for
that particular blend drop. Deviations from the desired shade can
also occur because of operator error associated with measuring and
combining the granules for the blends from the original supplies of
pure-colored granules. Sometimes defects or variations in shades or
colors cannot be detected during the manufacturing of the shingles.
In such cases the defect may not be discovered until the shingles
are actually installed on a roof. It would be advantageous if there
could be developed a method for monitoring the color of the various
blend drops during the shingle manufacturing process.
SUMMARY OF THE INVENTION
[0010] The above objects as well as other objects not specifically
enumerated are achieved by a method of producing asphalt strip
shingles including depositing blend drops of blend drop granules
onto an asphalt coated sheet, sensing the color of the blend drops;
comparing the sensed color of the blend drops with a reference
color, and providing a signal indicative of the comparison.
[0011] According to this invention, there is also provided a method
of producing asphalt strip shingles including continuously coating
a substrate with asphalt to form an asphalt coated sheet, moving
the asphalt coated sheet in a machine direction, depositing blend
drops of blend drop granules onto the asphalt coated sheet from a
blender, providing a signal indicative of the presence of the blend
drops at a location downstream from the blender, sensing the color
of the blend drops at the downstream location with a sensor,
comparing the sensed color of the blend drops with a reference
color, and providing a signal indicative of the comparison.
[0012] According to this invention, there is also provided a method
of producing asphalt strip shingles including making shingles of a
first color on a shingle machine including programming a controller
with a reference color, depositing blend drops of blend drop
granules onto an asphalt coated sheet, sensing the color of the
blend drops, comparing the sensed color of the blend drops with the
reference color, and providing a signal indicative of the
comparison. The shingle machine is switched to make shingles of
another color. Then the shingle machine is switched back to again
make shingles of the first color, using the programmed reference
color for comparing the color of the blend drops.
[0013] Various objects and advantages of this invention will become
apparent to those skilled in the art from the following detailed
description of the preferred embodiment, when read in light of the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic elevational view of an apparatus for
making shingles according to the invention.
[0015] FIG. 2 is a schematic view in elevation of the blender
portion of the apparatus of FIG. 1.
[0016] FIG. 3 is a schematic view in elevation, taken along line
3-3 of FIG. 1, of the granule coated asphalt sheet and the
apparatus of the invention for monitoring the color of the various
blend drops on the sheet.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now to the drawings, there is shown in FIGS. 1 and
2 an apparatus or shingle machine 10 for manufacturing an
asphalt-based roofing material according to the invention. The
illustrated manufacturing process involves passing a continuous
sheet 12 of shingle mat in a machine direction (indicated by the
arrows) through a series of manufacturing operations. The sheet
usually moves at a speed of at least about 200 feet/minute (61
meters/minute), and typically at a speed within the range of
between about 450 feet/minute (137 meters/minute) and about 800
feet/minute (244 meters/minute).
[0018] In a first step of the manufacturing process, a continuous
sheet of substrate or shingle mat 12 is payed out from a roll 14.
The substrate can be any type known for use in reinforcing
asphalt-based roofing materials, such as a nonwoven web of glass
fibers. The shingle mat can be temporarily stored on a mat
accumulator 16 to handle variations in demand and supply. Shingle
mat 12 from the accumulator is fed through a coater 18 where an
asphalt coating is applied to the sheet. The asphalt coating can be
applied in any suitable manner. In the illustrated embodiment, the
sheet is submerged in a supply of hot, melted asphalt coating to
completely cover the sheet with the tacky coating. However, in
other embodiments, the asphalt coating could be sprayed on, rolled
on, or applied to the sheet by other means. Typically the asphalt
material is highly filled with a ground stone filler material,
amounting to at least about 60 percent by weight of the
asphalt/filler combination.
[0019] The resulting asphalt coated sheet 20 is then passed beneath
the granule blender indicated generally at 22 for the application
of granules to the upper surface of the asphalt coated sheet 20.
The granule dispensers can be of any type suitable for depositing
granules onto the asphalt coated sheet. A preferred granule
dispenser is a granule blender of the type disclosed in U.S. Pat.
No. 5,520,889 to Burton et al, which is hereby incorporated by
reference, in its entirety. The granule blender is shown in more
detail in FIG. 2, and its operation will be discussed below.
[0020] After all the granules are deposited on the asphalt coated
sheet 20 by the blender 22, it becomes a granule covered sheet 24.
The granule coated sheet 24 is turned around a slate drum 26 to
press the granules into the asphalt coating and to temporarily
invert the sheet so that the excess granules will fall off. These
unattached granules are collected and reused. The granule covered
sheet 24 is subsequently fed through a cooling section 28 where the
temperature of the granule coated sheet 24 is reduced to give the
sheet the desired handleability characteristics for cutting and
packaging shingles. After the granule coated sheet 24 moves through
the cooling section 28, the sheet is fed into the looper 30 where
the granule coated sheet is temporarily stored until the sheet is
delivered to the shingle cutter and packaging apparatus, both not
shown. The cutter cuts the granule coated sheet 24 into lanes and
cuts each lane into individual shingles. The cutter may also cut
the shingles into designs having cutouts and tabs, depending on the
desired design for the shingle.
[0021] As shown in FIG. 2, the granule blender 22 includes four
blend drop hoppers 34, 36, 38, and 40. The final hopper is the
background hopper 42. Each of the hoppers is supplied with granules
from sources of granules, not shown. After the blend drops are
deposited on the asphalt coated sheet 20, the remaining, uncovered
areas are still tacky with warm, uncovered asphalt, and the
background granules from hopper 42 will adhere to these areas that
are not already covered with blend drop granules. Typically, the
granules applied by the background hopper 42 are made up by
collecting the backfall granules falling from the slate drum
26.
[0022] The hoppers 34, 36, 38, 40 and 42 can be of any type
suitable for being employed to accurately deposit a blend drop of
granules on the sheet. A preferred type of hopper is a
pneumatically assisted and controlled hopper as disclosed in U.S.
Pat. No. 5,520,889 to Burton et al. Each of the hoppers 34, 36, 38,
and 40 deposits a blend drop of a different color or shade onto the
asphalt coated sheet 20. Although blend drops can be of any size, a
typical length for a blend drop is about 14 inches. At typical web
speeds of hundreds of feet per minute, the flow of granules from
any one of the hoppers 34, 36, 38 and 40 must be turned on and off
in a very short time, i.e., a matter of a few seconds. Therefore,
the hoppers must be provided with highly effective on and off
gates. Also, in order to achieve the designed look or appearance of
the shingles when assembled on a roof, the timing of the four blend
drops from the four blend drop hoppers 34, 36, 38 and 40 must be
precise. For that purpose, a blender controller 44 is connected to
each of the hoppers 34, 36, 38 and 40. The blender controller
provides a signal to each of the hoppers to initiate the blend
drops and to conclude the blend drops. The blender controller can
be any electronic controller suitable for providing the proper
sequence and duration of the blend drops of each blend drop color,
and of the background color.
[0023] As is well known in the art, blend drops applied to the
asphalt coated sheet are often made up of granules of several
different colors. For example, one particular blend drop that is
supposed to simulate a weathered wood appearance might actually
consist of some brown granules, some dark gray granules and some
light gray granules. When these granules are mixed together and
applied to the sheet in a generally uniformly mixed manner, the
overall appearance of weathered wood is achieved. For this reason,
the blend drops are referred to as having a color blend, which
gives an overall color appearance, and this overall appearance may
be different from any of the actual colors of the granules in the
color blend. Also, blend drops of darker and lighter shades of the
same color, such as, for example, dark gray and light gray, are
referred to as different color blends rather than merely different
shades of one color.
[0024] Conventional shingle making machines use a wide shingle mat
and continuously make three or four lanes of shingles at once. As
shown in FIG. 3, the four lanes are indicated at 48, 50, 52 and 56,
respectively. Headlap granules are applied by the background hopper
42 to the headlap areas, indicated at 56, that are positioned
between adjacent shingle lanes. The blend drops from the first
blend drop hopper are indicated at 60 on the granule coated sheet
24. The blend drops from the second, third and fourth hoppers are
indicated at 62, 64 and 66, respectively. The background areas are
indicated at 68.
[0025] As further shown in FIG. 3, at a downstream location 72 a
sensor 74 is provided to view the blend drops for purposes of
determining their color. Preferably, the sensor is an optical
sensor. More particularly, the sensor 74 measures the visible
spectrum reflected from the blend drops 60, 62, 64 and 66 and sends
a signal to a color controller 76, the signal being indicative of
the color detected by the sensor. A light source 78 is provided
with the sensor 74. Preferably, the light source 78 is a strobe
light mounted with the sensor and capable of rapid on and off
flashing of light. Each flash of the strobe light source 74
generates a reflected image for the sensor 74, and thereby
originates a signal back to the color controller 76. Preferably,
the sensor 74 is a spectrophotometer. Equipment that can be used
for sensing the color of the blend drops is available commercially
from Fife Corporation, Oklahoma City, Okla., under the trade name
InSpectra.TM.. A system using this equipment can include a display
monitor and an operator interface operator.
[0026] The color controller 76 can be programmed with ranges of
color acceptability for each of the blend drops. The controller
includes a comparator that compares the sensed color of a blend
drop with the predetermined range of color for that blend drop. If
the sensed color is within the predetermined range, the color is
acceptable. The color controller 76 can be programmed to generate
various responses if the sensed color is outside the predetermined
range. For example, an alarm could be sounded. Other responses
could include changing the speed of the asphalt coated sheet and
changing or adjusting the color of the granules in the blend.
[0027] An optional feature of the invention is a stabilizer plate
80 positioned beneath the granule coated sheet 24 for helping
assure that the sheet is stable and not vibrating.
[0028] In view of the fact that there are four different colors of
blend drops as well as the background color granules that will be
viewed by the sensor 74, it is important to be sure that the sensor
is accurately aligned with the blend drops 60, 62, 64 and 66.
Preferably the sensor 74 is aligned with or focused on the center
of each blend drop being viewed at the time that the strobe
flashes. To provide information for the sensing operation (the
strobe 78 and sensor 74) a signal is sent from the blend drop
controller 44 to the strobe light source 78 via the color
controller. A timing device, such as a clock or a pulse generating
tachometer, not shown, is used to provide an accurate timing
sequence to provide the appropriate signal to the strobe 78 to
indicate the presence at the downstream location of the blend drop
to be measured. There is a time lag between the time the blend drop
is added to the asphalt coated sheet 20 and the time the sensor 74
is to view the blend drop. During operation of the shingle machine
this time lag will vary with the speed of the sheet 24.
[0029] In order to be able to view all the blend drops of a
four-wide shingle making machine of the type illustrated in the
drawings, the sensor 74 and strobe 78 are mounted on a movable
track 82. A motor 84 or any other suitable device is connected to a
carriage, not shown, on which the sensor and strobe are mounted to
move the sensor and strobe across all four lanes 48, 50, 52 and 54
of the sheet 24. It can be seen that the granule coated sheet 24 is
moved in a machine direction, and the sensor 74 is moved across the
granule coated sheet in a cross-machine direction to sense the
color of the blend drops 60, 62, 64 and 66. It is to be understood
that the sensing can be accomplished when the sheet is moving
vertically as well as in the horizontal orientation shown in FIG.
3.
[0030] In one embodiment of the invention, the color of the blend
drops from one of the hoppers is sensed for a period of time,
including the blend drops of that color across the entire width of
the granule coated sheet, as viewed by the sensor as it traverses
in the cross-machine direction. Then, the color measuring equipment
is switched to a mode where sensing the blend drops from another of
the hoppers occurs. Whenever such a switchover occurs, a short
delay in the resumption of sensing the color of the new bled drops
can be observed. This suppression of the trigger signal to the
strobe 78 will enable the granule coated sheet passing the blender
to reach the downstream location before the color measuring process
resumes on the new blend drops.
[0031] One particularly advantageous use of the method of the
invention is in the production of asphalt shingles that are
designed to simulate slate tiles. In such a case, each tab of the
shingles is provided any one of several colors according to the
color scheme. It is important that each blend drop be completely
true to its designed color.
[0032] Another advantageous use of the method of the invention is
that when shingle machines are switched from a first color to
another color, and then returned to the first color, the sensor can
assure that the color of the blend drops is within the desired
specification upon restarting the shingle machine in production of
the first color. For example, when switching from brown shingles to
black shingles and back to brown shingles, the sensor can assure
that all the blend drop colors associated with the brown shingles
are within specification. The color controller can maintain the
color specifications for each blend drop in its memory.
[0033] Although the invention has been described as having four
blend drop hoppers 34, 36, 38 and 40 for applying four different
blend drops 60, 62, 64 and 66, it is to be understood that any
number of different blend drops can be used with the invention.
[0034] The principle and mode of operation of this invention have
been described in its preferred embodiments. However, it should be
noted that this invention may be practiced otherwise than as
specifically illustrated and described without departing from its
scope.
* * * * *